diff --git a/sql/wsrep_sst.cc b/sql/wsrep_sst.cc
index 08a3d159e94..13500a83f43 100644
--- a/sql/wsrep_sst.cc
+++ b/sql/wsrep_sst.cc
@@ -1840,6 +1840,8 @@ wait_signal:
       else
       {
         WSREP_WARN("Received unknown signal: '%s'", out);
+        /* since it is the end of the loop, we must set error code */
+        err=-EINVAL;
         proc.wait();
       }
     }